Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations only declare readOnlyHint=true, so the description carries the behavioral load and does so well by disclosing the async state machine (status: pending | completed | failed) and when image_url populates. It stops short of error handling, rate limits, or auth needs, but the polling lifecycle is genuinely useful context beyond the annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

One sentence, tightly packed with the action, the polling use case, the status values, and the API route — no filler, and the core action is front-loaded.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description compensates by naming the returned status values and the image_url field, which is what an agent needs to interpret the response. Minor gaps (auth, failure recovery) remain but are not critical for this simple read tool.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100% and the sole parameter already documents its origin ('from a create_image response'). The description adds no parameter-level detail beyond that, so the baseline 3 is appropriate for a single fully-documented param.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('Get a single generated image') and the scope word 'single' implicitly separates it from bannerbear_list_images. The added API route (GET /v2/images/{uid}) makes the operation unambiguous.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Tells the agent exactly when to reach for this tool: 'poll this to check an async render', which is the key usage pattern after create_image. It doesn't name alternatives or exclusions explicitly, but the async-polling context is clear.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.